Can the U.S. Legally Kill Citizens Abroad?

Attorney General Eric Holder on Monday outlined the Obama administration's legal rationale for killing U.S. citizens in foreign countries, as it did in 2011 with the airstrike that killed suspected al-Qaida operative Anwar al-Awlaki in Yemen.

Holder, speaking at Northwestern University Law School, said the government authorizes targeted killings against U.S. citizens only after a careful review that finds the citizen poses an imminent threat of attack against the United States, that capture is not a viable option, and that the killing would be in line with the laws of war.

Does the United States have the legal authority to kill U.S. citizens abroad if it suspects them of being terrorists?

University of Virginia School of Law professor Saikrishna Prakash is an expert on constitutional law and presidential powers.

"I believe the 2001 Authorization [for Use of Military Force Against Terrorists] permits the president to use military force against al-Qaida and the Taliban. If the president determines that a U.S. citizen is a member of either group, he may use military force against that citizen. Apparently the president concluded that al-Awlaki was a member of al-Qaida and he further concluded that an attack was warranted. The president's actions were wholly consistent with domestic law."

Thomas Nachbar

UVA Law professor Thomas Nachbar, a judge advocate in the U.S. Army Reserve, has worked extensively on national security issues, including on detention law and policy and the role of legal institutions in counterinsurgency and stability operations.

"It's a very complicated question, in part because there are so many overlapping legal frameworks — both international and domestic — applicable to such a decision. There has been considerable debate as a matter of international law as to which legal framework applies — a great deal of dispute over whether to apply international human rights law as defined by instruments such as the International Covenant on Civil and Political Rights or the law of armed conflict as defined by instruments such as the Geneva Conventions. Not only are there disputes about which framework to apply, but the existence of considerable customary international law in both the human rights and law-of-armed-conflict settings makes determining how to apply the law under either framework difficult, even if everyone could agree on a framework.

I don't think there is much dispute that as a matter of the law of armed conflict, someone like al-Awlaki would be a valid target, much as Osama bin Laden himself was. It really comes down to the nature of his conduct toward the United States in the current conflict, which all sides seem to be treating as an armed conflict and therefore subject to the law of armed conflict, even if there has been some argument about it. Other than possible differences in his conduct toward the United States, the only thing that distinguishes al-Awlaki from Osama bin Laden is his U.S. citizenship, which, for purposes of the applicable law of armed conflict, is irrelevant.

But the greater complication that al-Awlaki's citizenship poses is as a matter of U.S. domestic constitutional law, and here we are in, if not uncharted territory, at least territory whose charting is "in progress." On the one hand, it seems inconceivable that the U.S. government can go around targeting citizens with drones, regardless of whether that happens inside or outside U.S. territory. On the other hand, it seems inconceivable that the U.S. cannot defend itself against an armed enemy, citizen or non-citizen, using military means such as drones. Where any particular use of force falls in that continuum, though, is the hard question, and one that is controlled by rules that are being written in the course of being applied."

"The administration may have legal authority to kill certain individuals under narrow circumstances of recognized armed conflict. Outside of such circumstances, the conditions sanctioning targeted killing of civilians are even more restrictive. Although U.S. citizens have a presumption of constitutional due process, the lawfulness of U.S. policy on targeted killing should apply to citizens and non-citizens equally. Constitutional due process usually means that substantive and procedural safeguards exist to ensure the legality of a government act. It also means that acts of the government are reviewable, particularly the intentional killing of a human being, however strong the justifications appear at the time.

The executive branch must anchor its authority in some legal regime that is consistent with both domestic and international law. The legal regime governing the lawfulness of targeted killing includes international humanitarian law (IHL, or the law of armed conflict) and international human rights law. IHL allows targeted killing when the target is a 'combatant' or 'fighter' or a civilian 'directly participating in hostilities.' In addition, the killing must be absolutely necessary under the circumstances (i.e., less harmful means of apprehension are unavailable), and the use of force must be proportionate so that any anticipated military advantage is considered in light of the expected harm to civilians and everything feasible must be done to prevent mistakes and minimize such collateral harm. Under human rights law, it is never permissible for killing to be the sole objective of an operation. However, human rights law links the right to self-defense with states’ obligation to exercise 'due diligence' to protect the lives of individuals from attacks by criminals, including terrorists. Human rights law permits targeted killing only if required to protect life (making lethal force proportionate) and no other means, e.g., capture or nonlethal incapacitation, exists to prevent that threat to life (making lethal force necessary). But even the Israeli Supreme Court (which ruled on the legality of targeted killing in a 2006 decision) rejected the argument that terrorists are unlawful combatants subject to attack at all times.

IHL and human rights law require transparency and accountability. While Attorney General Holder’s statement is a positive step in this regard, some core legal questions remain unaddressed. These include who qualifies as a lawful target, and where and when the person may be targeted. Like the previous administration, the Obama administration argues that the scope of armed conflict in which the U.S. is engaged is unrestrained by any declaration of war. The failure to disclose procedural and other safeguards that ensure killings are lawful, and the accountability mechanisms that ensure wrongful killings are investigated, prosecuted and punished, leave the administration open to the charge that its targeted killing policy violates international law."

Is It Legal? is an occasional feature in which UVA law professors weigh in on legal aspects of current events.